1. Field
A rechargeable lithium battery is disclosed.
2. Description of the Related Art
A lithium polymer battery may be manufactured to have various shapes, such as a thin film, and accordingly, may be applied to a small information technology (IT) device, such as a smart phone, a tablet PC, a net book, and the like.
As such IT devices gradually require higher and higher performance, the battery used therein is expected to have higher capacity. As the rechargeable lithium battery is expected to have higher capacity, graphite as a negative active material may not realize sufficient or suitable high-capacity as expected for the rechargeable lithium battery.
Accordingly, a silicon-based active material has drawn attention as a negative active material due to its higher charge and discharge capacity than the graphite. However, the silicon-based active material has a sharp cycle-life deterioration, since an electrolyte is exhausted due to a reaction of silicon in the negative electrode with the electrolyte as a result of the repeated charge and discharge cycles.